Electrical heating device



May 5, 1942.

G. H. MOREY ELECTRICAL HEATING DEVICE Filed Sept. 20, 1946 2Sheets-Sheet 1 May 5, 1942. s. H. MOREY ELECTRICAL HEATING DEVICE FiledSept. 20, 1940 2 Sheets-Sheet 2 Patented May 5, 1942 UNITED STATESPATENT OFFICE v 2,282,078 ELECTRICAL HEATING DEVICE Glen H. Morey, TerreHaute, Ind.

Application September 20, 1940, Serial No. 357,621

9 Claims.

My invention relates to heating devices, and more particularly toheating devices adapted to heat glass or other fragile vessels,

In my co-pending application Serial No. 271,- 057, flied May 1, 1939, Ihave described a heating device especially adapted for heating glassdistilling flasks. This device is a completely flexible structure whichis especially advantageous from the standpoint of protecting the vesselfrom mechanical shock. However, in view of its flexible nature, thisdevice must be supported by the vessel itself, or special supportingmeans of necessarily complicated structure must be provided.

An object of my present invention, therefore, is to provide a heatingdevice for glass or other fragile vessels which may itself support thevessel. A further object of my invention is to provide such a devicewhich will not only support the vessel, but will at the same timeprovide only a flexible, resilient surface in contact with the vesseland thus protects it from external mechanical shocks or from shockscaused by bumping of liquids boiling in the vessel. Another object of myinvention is to provide a heating device of this character havinggeneral application for heating vessels in laboratory and industrialuse, and for heating home utensils such as vacuum coffee makers and thelike. Additional objects and advantages of my invention will be evidentfrom the following description.

In the drawings, wherein like reference characters indicate like orcorresponding parts:

Fig. 1 is a top plan view of a heating device embodying the presentinvention;

Fig. 2 is a transverse sectional view through the device illustrated inFig. 1;

Fig. 3 is a view similar to Fig. 1 of a modifled form of the invention;and

Fig. 4 is a transverse sectional view of the device illustrated in Fig.3.

The heating device of my present invention comprises, briefly, an innermember formed of flexible woven fireproof fabric shaped to conformclosely to the exterior of at least the lower portion of the vessel tobe heated, a substantially rigid outer member surrounding the innermember, and a cushioning layer of resilient heat insulating materialinterposed between said inner and outer members. An electrical heating Apreferred modification of my invention is illustrated in Fig. 1 of theaccompanying drawings, representing top and cross-sectional views of aheating device adapted to heat vessels of substantially spherical lowersections, such as distilling flasks and the like. As may be seen fromthe drawings, the heating device comprises, as its main elements, aninner member I, an outer member 2, a heating element 3, and resilientheat insulating material 4 interposed between said inner and outermembers,

The inner member I is formed of flexible woven fireproof fabric such asglass cloth, and is shaped to flt the vessel to be heated, by stretchingover a form, taking tucks or making darts in the fabric, or cutting amulti-lobed pattern which, on sewing together, will form the desiredshape. The fabric is preferably cut in such a manner as to provide anoutwardly extending annular lip 5, at the periphery of thevessel-receiving opening of the formed member I.

The outer member 2 may suitably be formed of metal, and may be cast,drawn, or spun to conform approximately to the shape of the inner memberI. The outer member 2 is provided with an inwardly extending annular lip6, adapted to engage the annular lip 5 of the inner member I. The lip 6may suitably be drilled and tapped to receive screws I which serve tohold a clamping ring 8 against the annular lip 5. The annular fabric lip5 of the inner member I is thus clamped between the ring 8 and theannular lip 8 of the outer member 2.

Between the inner member I and the outer member I is interposedresilient heat insulating material I, which may comprise asbestosflbers, glass wool, slag wool, magnesia" in comminuted form, or othersimilar materials. The material 4 may suitably be packed, matted, orfelted into a substantially uniform cushion to provide resilient supportfor the inner member I at all points where said member contacts thevessel to be heated.

The electrical heating element 3 preferably comprises a helicalresistance element aflixed to the inner member I, with its turns sospaced and locked to the woven structure of the member I as to preventshort-circuiting on flexing of the said member I. The heating element 3may be attached to the member I in any suitable manner to effect thisend, for examplesimply by stitching the resistance element to the fabricby means of fireproof thread such as thread formed of glass fibres. Thepower leads 9 for the heating element 3 may pass through a suitableopening in the member 2, which is preferably provided with an insulatinggrommet to.

Any desired type of mounting means may be provided for the heatingdevice. A convenient form for laboratory uses of these heaters isillus-- trated in Fig. 1. This comprises a boss I I, which may, forexample, be cast integrally with the member 2, and which is drilled andtapped to receive a threaded-rod I! of the standard type adapted to beclamped in laboratory ring-stand clamps,

Another modification of my heating device is illustrated in Fig. 2 ofthe accompanying drawings, representing top and cross-sectional views ofa heater especially adapted for heating vacuum cofiee makers. Thismodification difiers from that of Fig. 1 in that the outer member 2 is abox-like structure providing its own supporting base, and the innermember is formed of two layers of fireproof fabric I and I, rather thanmerely a single layer. In this case the outer member 2 may suitably bemolded of heat-resistant plastic, or may be formed of otherheatresistant material such as asbestos board. The member 2 may also beformed of metal as in the previous modification, or, on the other hand,may be formed of material of low heat resistance if sufiicient heatinsulating material 4 is provided. The provision of a double layer offabric Il' comprising the inner member enables the electrical heatingelement 3 to be fixed in position by stitching the resistance wire intothe woven structure of the layer I. By thus stitching or weaving thewire into the fabric layer I, the separate turns are securely locked innon-shorting relationship. When employing the double layer of fabricll', both layers are preferably provided with annular lips 55' forclamping between the ring 8 and the annular lip 6 of the outer member 2.

In the operation of either of the devices described above, the vessel tobe heated is merely placed in the heater, resting on the inner member I,the leads 9 are connected to a power source, and sufficient current ispassed through the resistance element 3 to heat the contents of thevessel to the desired degree. When boiling liquids with these heatingdevices, the very uniform heating which is provided reduces to a markedextent the bumping which is otherwise normally encountered, and theresilient construction provided by the flexible inner member l and thecushioning material 4 adequately 'outer construction, also providesadequate pro tection for the vessel from external mechanical.

shocks.

It is to be understood, of course, that the particular heating devicesdescribed above are mere- 1y illustrative, and do not limit the scope ofmy invention. Various equivalent constructional materials may beemployed, as, for example, the use of fabrics formed of asbestos, slag,or rock fibres instead of glass fibres. Various modifications ofconstruction will also be evident to those skilled in the art, as, forexample, the provision of other clamping or att ching means for afllxingthe inner fabric mem er to the rigid outer member of the device. Also,it will be apparent that two or more units may be pro-' vided in orderto heat the upper as well as the lower portions of any vessel. Ingeneral, it may and the use of any equivalents which would normallyoccur to one skilled in the art are included in the scope of myinvention.

My invention now having been described, wha I claim is:

1. A heating device adapted to receive and support a glass vessel andheat the same, comprising an inner member formed of at least one layerof flexible woven fireproof fabric shaped to conform closely to theexterior of the lower portion of said vessel, a substantially rigidouter supporting member surrounding said inner member but spaced fromthe vessel contacting portion thereof, means for attaching said innermember at the periphery of its vessel-receiving opening to said outersupporting member, an electrical heating element aflixed to the wovenstructure of said inner member in spaced and non-shorting relationship,and resilient heat insulating material interposed between said inner andouter members to provide resilient support for'said inner member and forsaid vessel, and to protect said vessel from mechanical shock.

2. The heating device of claim 1 in which the inner member is formed offlexible woven glass cloth.

3. The heating device of claim 1 in which the inner member is formed offlexible woven glass cloth and the heat insulating material comprisesglass wool.

4. A heating device adapted to receive and support a glass vessel andheat the same, comprising an inner member formed of at least one layerof flexible woven fireproof fabric shaped to conform closely to theexterior of the lower portion of said vessel, a substantially rigidouter supporting member surrounding said inner member, said outer memberhaving an inwardly extending lip adapted to engage the edge ofsaid'inner member at the periphery of its vesselreceiving opening,clamping means adapted to co-operate with said lip and hold theperipheral edge of said inner member against said lip by pressureengagement, an electrical heating element interposed between said innerand outer members in spaced and non-shorting relation-' ship, andresilient heat insulating material interposed between said inner andouter members to provide resilient support for said inner member and forsaid vessel, and to protect said vessel from mechanical shock.

5. The heating device of claim 4 in which the inner member is formed offlexible woven glass cloth.

6. The heating device of claim 4 in which the inner member is formed offlexible woven glass cloth, and the heat insulating material comprisesglass wool.

7. A heating device adapted to receive and support a glass vessel andheat the same, comprising an inner member formed of at least one layerof flexible woven fireproof fabric shaped to conform closely to theexterior of the lower portion of said vessel and having an outwardlyextending annular lip at the periphery of its vessel-receiving opening,a substantially rigid outer supporting member surrounding said innermember and spaced therefrom, clamping means for attaching the outwardlyextending annular lip of said inner member to said outer supportingmember, an electrical heating element interposed between said inner andouter members and afilxed to the woven structure of said inner be saidthat the use of any such modifications,

inner member is formed of flexible woven glass cloth.

9. The heating device of claim 7 in which the inner member is formed offlexible woven glass cloth and the heat insulating material comprisesglass wool.

GLEN H. MOREY.

